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  <title>Document</title>
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  <script>
    for(var i = 0; i < 5; i++) {
      
      if(i === 3) {
        break  // 跳出整个循环
      }

      // if(i === 3) {
      //   continue  // 结束本次循环， 执行下一次
      // }
      console.log( i )  // 0 1 2  4
    }
  </script>
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